QT解析json

QT解析json

QJsonDocument结合QVariant进行解析

{
    "bsType": 0,
    "setId": 1000,
    "mainInfo": [
        {
            "cpuType": "i7-8550",
            "coreNum": 8,
            "mainFrequency": "2.4GHz",
            "diskType": "Cme-China",
            "diskTotolSize": 1024,
            "disks":[   
                {"diskName": "C:", "diskSize":256, "usedSize":120, "usedRatio":0.6, "uflag":0},
                {"diskName": "D:", "diskSize":256, "usedSize":100, "usedRatio":0.2, "uflag":1},
                {"diskName": "E:", "diskSize":512, "usedSize":300, "usedRatio":0.2, "uflag":0}
            ]                
        }
    ]
}

解析json实例

#include <QCoreApplication>
#include <QFile>
#include <QJsonDocument>
#include <QVariantMap>
#include <QDateTime>
#include <QJsonObject>
#include <QDebug>

QByteArray readJson(const QString &jsonFile)
{
    QFile file(jsonFile);
    if(file.open(QIODevice::ReadOnly) == false)
    {
        return QByteArray("");
    }

    QByteArray jsonStr = file.readAll();
    file.close();
    return jsonStr;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QByteArray bytearray = readJson("./Untitled.json");
    QJsonParseError jsonErr;
    QJsonDocument jsonDoc = QJsonDocument::fromJson(bytearray, &jsonErr);
    if(jsonErr.error != QJsonParseError::NoError)
    {
        qDebug()<<QString::fromLocal8Bit("Json文件解析失败:");
        return a.exec();
    }
// qDebug() << jsonDoc.toVariant().toMap()["mainInfo"];
// QVariantMap jsonMap = jsonDoc.toVariant().toMap();//当前那一层是{}使用
// QList<QVariant> MonitorList = jsonDoc.toVariant().toList();//当前那一层是数组[]的时候使用
    QList<QVariant> MonitorList = jsonDoc.toVariant().toMap()["mainInfo"].toList();
    for(auto &MonitorItem : MonitorList)
    {
        QVariantMap MonitorMap = MonitorItem.toMap();
        qDebug() << MonitorMap["cpuType"];
        qDebug() << MonitorMap["coreNum"];
        qDebug() << MonitorMap["mainFrequency"];
        qDebug() << MonitorMap["diskType"];
        qDebug() << MonitorMap["diskTotolSize"];
// qDebug() << MonitorMap["disks"];
        QList<QVariant> slist = MonitorMap["disks"].toList();
        for (auto &item: slist)
        {
            QVariantMap sMap = item.toMap();
            qDebug() << sMap["diskName"];
            qDebug() << sMap["diskSize"];
            qDebug() << sMap["usedSize"];
            qDebug() << sMap["usedRatio"];
            qDebug() << sMap["uflag"];
        }
    }
    return a.exec();
}

json的写入

QVariantMap map;  
map["address"] = QString("192.168.0.1");  
map["name"] = QString("xie");  

QString data = QJsonDocument::fromVariant(map).toJson(QJsonDocument::Indented);//带有格式。  
                                            QJsonDocument::Compact(没有格式)